Summary

User picker "in group" filter does not display all users when having more than 1.000 users on JIRA.

Steps to Reproduce

1. Deploy a clean 7.2.6 instance;
2. Use the JIRA Data Generator to create 1.100 random users;
3. Manually create 5 users and add them to a test-user group;
4. Open the "User Picker", we'll notice that not all users from JIRA are picked as per message "Displaying users 1 to 20 of 1,000" on the screenshot below;
   
5. On the "In Group" field, select the "test-user" group and hit the "Filter" button;

Expected Results

• All 5 users added to the test-group to be displayed;
  

Actual Results

• Not all users are displayed;
  

Workaround

Use the user management view to filter the users from the group instead using the user picker.